Field
The present application relates to an actuator, particularly a bistable actuator, for a surgical instrument, particularly an endoscope, with a sliding tube to accommodate a rotor and a rotor arranged in said sliding tube. Furthermore, the present application relates to a rotor positioning key for a rotor of a, particularly bistable, actuator.
Prior Art
An endoscope with a distally arranged objective is known from DE 196 18 355 C2, the image of which is forwarded to the proximal end by an image forwarder and that has at least one optical element like a lens group, which is shiftable in the direction of the optical axis for focussing and/or for changing the focal length by a microdrive, wherein the microdrive has at least one rotationally symmetrical axially movable sleeve, which surrounds and receives the lenses or respectively the optical element of the movable lens group and wherein the sleeve is made of a permanently magnetic material and is movable in a magnetic field, which is generated by a spool arrangement. In order to move and to hold the sleeve, an electromagnetic field is generated continuously.
An endoscope with a distally radiating illumination device for a body cavity part to be observed and an image conductor is known from DE 1 253 407 B, which captures the illuminated image via an objective that is adjustable in the axial direction and directs it to an ocular or a camera, wherein the objective is adjustable for at least two image sharpness settings from one position into another position with respect to the distal end of an image conductor through electromagnetic manipulation of an objective mount serving as an anchor. At least one of the two positions is hereby evoked by a permanently present electromagnetic field and the other position by the effect of a spring.
Moreover, an electromagnetic actuator for a surgical or medical instrument, in particular an endoscope, is described in DE 10 2011 006 814 A1.